VD-ОKО-01 universal eddy-current flaw detector


VD-ОKО-01 universal multi-channel eddy current flaw detector is intended for solving a wide range of eddy current flaw detection tasks in such branches of industry as:
AIRCRAFT testing of aeronautical engineering parts (wheel disks, skin, turbine blades, multilayered constructions etc.);

RAIL TRANSPORT testing of rail components and car units (parts of wheel pair and axlebox unit, load trolleys, refrigerated carriages and coaches, automatic coupler etc.).

OIL-AND-GAS testing of pipelines, pressure vessels etc.

CHEMICAL testing of pipelines, industrial vessels etc.

POWER testing of steam generator pipes by I/D ECP, collectors etc.

• ENGINEERING testing of rods, wire, metalwares, forming rolls, sheet metals, metal parts of bearing structures etc.


  • high efficiency due to flaw detector multi-channeling;
  • possibility of flaw detector application during mechanized and automated testing execution;
  • exclusion of human factor influence (if it is used as a part of mechanized testing system);
  • possibility of the evaluation of defect depth and length, and also LED and sound flaw alarm;
  • operation simplicity due to the intuitive interface;
  • registration of all testing results and extended capacities of data analysis.



  • large color high-contrast TFT display;
  • ALARM system: 4 three-color LEDs, sound alarm;
  • various scanning units manipulation;
  • USB slave;
  • possibility of up to two encoders connection;
  • possibility of software application for different testing tasks: testing of pipe bodies, rolled metals, wheel pairs, rods and wires etc.


  • flaw detector sensitivity threshold on artificial defects, such as "slit" on the calibration block: length – 2 mm; depth – 0,1 mm; opening –  from 0,1 mm;
  • operating frequency setup range – from 50 Hz to 12 МHz;
  • generator output voltage (double amplitude) – from 0,5 V to 16 V;
  • adjusted gain range – 52 dB;
  • digital filtering, 3 filter types: Bandpass, Differential, Averaging;
  • electronic instrument duct consists of 1 physical channel with possible multiplexing using outer commutators;
  •  possibility of 4 multiplex units connection;
  •  connection of up to 32 channels to one multiplex unit;
  • external synchronization;
  • LED (4 LEDs) and sound flaw alarm;
  • automatic (phase) tuning out from the influence of operating gap and inhomogeneity of electromagnetic properties of the testing object;
  • possibility of connection and operation of ECP of the following types:
    • differential ECP;
    • differential ECP connected according to the bridge scheme;
    • differential transformer ECP with grounded centerpoint;
    • differential transformer ECP;
    • absolute (parametric) ECP;
    • absolute transformer ECP;
  • eddy current signal display in various views:
    • display of 4 areas on one page;
    • MULTY mode – band charts each of which corresponds to a specific channel are displayed in one area;
    • complex plane (XY) – allow to detect defects among interferences by analyzing the signal form;
    • 2D- mode of two-dimensional defect display;
    • bar diagram (BAR).

  • time of flaw detector operation mode setup – up to 1 minute;
  • storing of instruments setups and testing results on compact-flash memory card;
  • mode of two-way connection with PC via USB port (for inputting the information from the flaw detector memory into PC and possibility of this data printing as well as setups loading from PC into the flaw detector memory);
  • encoder connection option;
  • four independent frames of automatic flaw alarm (ALARM) for each display area;
  • evaluation of defect depth and length;
  • channels mixing option;
  • possibility of signal display color selection for each channel and channels mix separately;
  • autozap function;
  • built-in clock and calendar;
  • screen backlight;
  • screen brightness control;
  • reception path overload check;
  • check of flaw detector memory fill;
  • storage battery discharge level indication;
  • friendly multi-language interface;
  • time of continuous flaw detector operation with the fully charged storage battery –  at least 8 hours;
  • flaw detector is powered from the following sources:
    • EPU with rated voltage of 12 V and rated capacity of 9 А×h;
    • AC mains with voltage from 187 V to 242 V, with frequency (50 ± 1) Hz.



By creating special scanners for VD-ОKО-01 instrument, it is possible to solve effectively the flaw detection tasks of metal units and parts in various branches of industry. As a result, VD-ОKО-01 flaw detector complete with scanners is a universal mechanized complex of non-destructive testing.

Today, VD-ОKО-02 eddy current flaw detector, together with scanners, solves the following tasks of eddy current flaw detection:

  • Testing of pipelines and sheet products
The series of VD-SCANNER multi-channel scanners on the basis of VD-ОKО-01 flaw detector is intended for carrying out mechanized eddy current testing of radial surfaces with different curvature radii in order to detect surface defects, such as longitudinal and transverse cracks, folds, scabs etc.

Production crack of 0,76 mm in depth and up to 60 mm in length detected during straight-line-seam pipe testing

Execution of main pipe body testing using VD-ОKО-01 flaw detector complete with VD-SCANNER02 8-mm channel scanner enabled to evaluate the pipe damage rate and its further operability
  • Testing of fillet transitions and radial surfaces
SKV-GP scanners family is intended for performing 100% mechanized testing of fillet transitions with various curvature radii on radial surfaces.

Signal from crack on the fillet transition with radius of 25 mm and depth of 0,54 mm detected during field inspection of forming roll

Carrying out of 100% eddy current testing of forming rolls using VD-ОKО-01 flaw detector and special scanning units allows to evaluate the damage rate of both roll working surface and fillet transitions


Speciality application-dependent software for processing the testing results of VD-ОKО-01 universal eddy-current flaw detector serves for functionality extension and instrument operation ease increase. This program provides operation with the data stored on PC.

Main advantages of program application are:

  • convenient view of testing results by each channel;
  • possibility of automatic scrolling of the stored defectogram at different speeds;
  • possibility of the displayed results type changing, namely the display of raw data in the mode:
    • MULTY;
    • 2D;
    • XY;
  • digital testing results processing with the usage of filters: Bandpass, Differential, Averaging.

The data received during inspection can be processed using digital filtering algorithms. This may improve signal/noise ratio, single out useful signal component or reject signals from interfering factors (zero drift, arm shake, testing object geometry change etc.).

Examples of digital filtering application in signals processing program:

Averaging filter

Averaging filter operation is similar to lowpass filter operation. Its aim is to remove high-frequency noise present in the signal and, thereby, increase signal/noise ratio. As a rule, it is applied when operating at high gains.

Pickup signal

Signal after using Averaging Filter


Bandpass filter

Signals received during testing of rotary cylinder sleeve with further processing by bandpass filter allow to suppress lowpass harmonic component related to the sleeve rotation.

Pickup signal

Signal after using Bandpass Filter


Differential filter

In a number of cases when the signal from the interfering factor has a pronounced periodic character, it can be efficiently eliminated (or minimized) with the help of differential filter.

Pickup signal

Signal after using Differential Filter
  • filters parameters setup;
  • ALARM unit setup;
  • calibration;
  • zooming, preset area changing, convenient diagrams scrolling;
  • defect depth evaluation;
  • output of the table with detected defect data, notably:
    • channel number via which ALARM went off;
    • defect position coordinate;
    • amplitude and phase of signal having transcended the threshold level;
    • defect depth.

  • Printing of eddy current testing report with the display of signals from defect.

Main specifications
Overall dimension of flaw detector without a handle and with one eddy current unit and power unit no more than 330 mm x 180 mm x 140 mm
Weight of flaw detector with one eddy current unit and power unit no more than 6 kg
Keyboard Russian
Languages Russian
Number of eddy current units  4
Number of channels in eddy current unit 32 channels
Connectors types Lemo-14, DB-15
Data storage flash card
Independent power source NiMH storage battery of rated voltage 12 V and rated capacity  9 А∙h
Operation time 8 hours
Power supply AC mains of voltage (220 В ± 10%) and frequency (50 ± 1) Hz
Flaw detector electric power consumed from AC mains no more than 30 V·А
Time of flaw detector operation mode setup no more than 1 min.
Display type NL8060BC21-03 (800×600 pixels)
Screen dimensions (width, height, diagonal) 170 mm × 130 mm, 214 mm
Warranty 1 year
USB Port USB slave, USB host
RS – 232 available
PS/2 two inputs
Trigger I/O available
Headphones available
Encoder output single-coordinate encoder
Main metrological performances
Protection level in operation IP 64
Ambient temperature from minus 10° to +40° С
Atmospheric pressure from 84 to 106,7 kPa
Relative humidity (93 ± 3) % at the temperature of 25 ºС
Flaw detector in shipping package is resistant to the influence of
  • vibrations
  • strokes with the peak shock acceleration value 98 m/s2, impulse duration 16 ms, number of strokes 1 000±10 for each direction
Flaw detector retains its parameters when it is influenced by electromagnetic interferences which do not exceed the following norms
  • harmonic interferences of magnetic field in the frequency band from 30 Hz to 50 kHz with the effective value of field intensity from 130 to 70 dB
  • harmonic interferences of electric field in the frequency band from 10 kHz to 30 МHz with the effective value of field intensity 120 dB
Full average flaw detector lifetime no less than 10 years
Output voltage (double amplitude) 0,5; 1; 2; 4; 8; 16
Operating frequencies range from 50 Hz to 2 МHz
Synchronization type internal, from encoder, from rotary ECP
Gain from 0 to 40 dB with a step of 1, 10 dB
Input signal no more than 0,5 V from peak to peak
Digital filters 3 digital filters: Bandpass, Averaging, Differential